An ink cartridge which is engaged with an inkjet printer mainly comprises a storage cavity for storing ink, an ink outlet for supplying ink to a printhead of the printer, and a detection component for detecting the ink cartridge and the ink level. For the sake of guaranteeing the normal operation of the ink cartridge after the ink cartridge is installed into the printer, the ink cartridge must comprise two detection mechanisms. When the ink cartridge is installed into the printer, firstly, one detection mechanism disables light transmitted by a transmitting section of a second sensor on the printer to return to a receiving section of the second sensor; secondly, with the ink cartridge installation, the light transmitted by the transmitting section of the second sensor could return to the receiving section of the second sensor; thirdly, the other detection mechanism disables light transmitted by a transmitting section of a first sensor on the printer to return to a receiving section of the first sensor; and finally, the light transmitted by corresponding transmitting sections of the first sensor and the second sensor cannot return to corresponding receiving sections of the first sensor and the second sensor, and the ink cartridge installation detection is completed herein, then the printer prompts to carry out the next operation. The technical measures for detecting the ink cartridge and the ink level are as follows: the detection mechanisms of the technical proposal mainly realize the detection by blocking light transmitted by sensors, and the operating principle of the detection mechanisms is as follows: when the ink cartridge is installed into the printer, firstly, light transmitted by the second sensor in the printer is blocked by a light-tight second detection component; secondly, the light transmitted by the second sensor is not blocked by the light-tight second detection component while light transmitted by the first sensor is blocked by a first detection component; and finally, the light transmitted by the second sensor is blocked by a light-tight third detection component and the light transmitted by the first sensor is blocked by the first detection component, and herein the printer prompts the existence of the ink cartridge and the admission of the next operation. The third detection component consists of a light-transmitting section and a light-tight movable member; the position of the movable member is varied with the ink level in the ink cartridge; and the ink level in the ink cartridge can be detected by the fact that whether the light transmitted by the second sensor is blocked by the third detection component or not.
As the movable member is arranged inside the ink cavity, the technology can cause ink cartridge installation detection error and ink level detection error due to the fact that the third detection component can be adsorbed due to the surface tension of ink.
In view of the defects of the ink cartridge, the patent CN200910105619.8 discloses another ink cartridge invented, namely an ink cartridge of which a movable member for detection is arranged outside an ink cavity, wherein the movable member can move along with a spring plate and is acted as the second detection component and the third detection component during the ink cartridge installation detection; and the movable member moves when a soft supporting cap is deformed with the varied ink level, and the ink-out detection is completed. A second detection mechanism matched with a second sensor on a printer is matched with the soft supporting cap which is arranged on a cartridge body and communicated with an ink storage cavity, and comprises the movable member, a shaft arranged inside the cartridge body, and the spring plate arranged on the ink cartridge; the movable member is connected with a rotating shaft of the cartridge body through the shaft; and the spring plate can abut against the lower edge of the movable member under the action of the gravity of the movable member. When the ink cartridge is installed, the spring plate does not abut against the movable member again, and the movable member moves around the shaft in virtue of the gravity and abuts against the soft supporting cap when not reaching the upright position, and the ink-out detection is completed. As illustrated in FIG. 1, the traditional ink cartridge 1 for the inkjet printer comprises an ink detection mechanism for detecting the ink level, a detection component 102 matched with a sensor on the printer, and a soft supporting cap 3 arranged on a cartridge body and communicated with an ink storage cavity. On one hand, after ink in the ink storage cavity is out, the soft supporting cap is deformed and light transmitted by the sensor is changed as well. However, as the hardness of the soft supporting cap is difficult to control, the detection error tends to occur in consideration of the gravity of a blocking component. On the other hand, when the soft supporting cap 3 does not support the blocking component, the blocking component moves in virtue of the gravity of the blocking component, When ink or other foreign substance is adhered to the blocking component, the movement deviation of a lever assembly can occur due to the tensile force of the ink or the adsorbability of the foreign substance, and the detection error of the sensor can occur as well. Therefore, the embodiments provided by the invention adopt the elastic force to overcome the process error of the second blocking component and the detection error caused by the foreign substance.
The technical proposal adopted by the above patent has the disadvantage that the process is difficult to realize as the mass of the movable member, the thickness of the soft supporting cap, and the pressure in an ink bag are difficult to control. For example, when the movable member has large mass and the soft supporting cap is relatively thin, maybe there is ink in the ink cartridge, but the soft supporting cap is not thick enough to support the movable member, thus causing the ink cartridge installation detection error of the ink cartridge and simultaneously causing the ink-out detection error.